CORRECTION: In the Dec. 13 story below about Colorado’s new rules governing the public disclosure of chemicals used in hydraulic fracturing operations, The Associated Press reported erroneously that Texas’ new rules will not require companies to disclose the concentration of chemicals used in their mixes. The companies will be required to disclose the concentration of chemicals regulated by the U.S. Occupational Safety and Health Administration, but will not be required to report the concentration of unregulated chemicals.

DENVER (AP/CBS4) – Colorado will require energy companies to disclose the concentrations of all chemicals in hydraulic fracturing and also ask drillers to make public some information about ingredients considered trade secrets.

Colorado regulators unanimously approved the new rules Tuesday that take effect in April.

The guidelines are similar to those required by a first-in-the-nation law passed in Texas this year but go further by requiring the concentrations of chemicals to be disclosed.

“That’s the big advancer here. We’re getting a full picture of what’s in that fracking fluid,” said Michael Freeman, an attorney for Earthjustice who worked with industry to write the rules.

Also, if Colorado drillers claim a trade secret, they would still have to disclose the ingredient’s chemical family. In emergencies, companies would have to tell health care workers what those secret ingredients were.

“It yielded a good rule for the state and a workable rule for the industry,” said Jep Seman, an attorney for the Colorado Petroleum Association.

Companies have been fracking for decades, but as drilling expands to more populated areas, residents near wells are concerned about the effects on their health and drinking water. Texas, in passing its law this summer, noted that fracking has been done safely in that state for 60 years.

Arkansas, Montana and Wyoming all require companies to disclose the chemicals in fracking fluid but not their concentrations, said Matt Watson, senior energy policy manager for the Environmental Defense Fund. Louisiana and New Mexico only require disclosure of some chemicals deemed workplace hazards by the Occupational Safety and Health Administration. Other states, including Michigan and Pennsylvania, have proposed similar regulations.

Gov. John Hickenlooper called for Colorado to draft a disclosure rule. The commission proposed having companies list nonproprietary ingredients and concentrations on FracFocus.org, a national website created by two intergovernmental agencies. The rule was proposed to take effect Feb. 1, but commission staff recommended delaying that until April 1 to give drillers more time to comply.

“I think we’ve reached the fairest and most transparent rules on the transparency of frack fluids of any state in the country,” Hickenlooper said afterward. “I think this will likely become a national model that if other states they don’t copy it, they will certainly use it as a touch point.”

Commission staff said a survey of Colorado disclosures on FracFocus.org shows a small percentage claim trade secrets, though the website includes only voluntary disclosures. Companies on the website say the fluid is mostly water mixed with sand and small percentages of petroleum chemicals and alcohols such as Isopropanol, which is used in rubbing alcohol, while some contain hydrochloric acid.

Freeman said some fracking fluids also might contain diesel fuel, benzene and other chemicals commonly found in gasoline. The database will be searchable by company, well location and type of chemical used.

The Environmental Protection Agency last week found a possible link between groundwater pollution and hydraulic fracturing beneath Pavillion, Wyo. The EPA found compounds likely associated with fracking chemicals in the groundwater beneath the small central Wyoming community where residents complain their well water smells like chemicals. Health officials last year advised residents not to drink their well water after the EPA found low levels of hydrocarbons.

Industry officials pointed out that the EPA announcement didn’t focus on the domestic water wells but two wells drilled somewhat deeper into the aquifer specifically to test for pollution. The owner of the Pavillion gas field, Calgary, Alberta-based Encana, said the compounds could have had other origins not related to gas development.

Commission Director Dave Neslin said the commissioners are reviewing the draft EPA report but Colorado already has implemented regulations meant to protect groundwater. Those regulations include how to properly encase and cement walls, clean up spills and properly dispose of waste.

“Disclosure is important for transparency and public education, but it’s not our first line of defense,” he said.

“I think that natural gas has a huge future in the energy portfolio of the United States. I also believe that people are going to be scared if they don’t know what is going into the underground and what is being injected,” Salazar said. “So I think disclosure is very much a step in the right direction in terms of promoting a healthy natural gas future for the country.”